X-ray fluorescence (XRF) analyzers can include an x-ray source and an x-ray detector. The source can include an electron emitter that is sealed inside of an x-ray tube. The x-ray detector can be sealed inside of an evacuated housing. The electron emitter can emit electrons towards a target that is also within the x-ray tube. The target can then emit x-rays out through a window in the x-ray tube towards a sample. The sample can absorb the x-rays from the source, then fluoresce elemental-specific, characteristic x-rays. The characteristic x-rays can pass through a window in the housing and impinge on the x-ray detector. The x-ray detector can then analyze sample chemistry.
It can be difficult to detect low-atomic-number elements (e.g. Z≤20 and especially Z≤17) because of x-ray attenuation by air. This air attenuation occurs between the sample and the window of the x-ray detector and within the detector housing if internal components emitted gasses (out-gassed) after the device has been evacuated and sealed.
Out-gassing can also cause reduced detector cooling (cooling is needed for improved sample analysis resolution). Out-gassing within the x-ray tube can result in gas ion formation due to the electron beam. These gas ions can cause electron spot instability and/or deterioration and early failure of the x-ray tube.
XRF analyzers can be costly due to the high cost of manufacturing two, separate, hermetically-sealed devices—the x-ray tube and the x-ray detector.